Various subterranean formations contain hydrocarbons in fluid form which can be produced to a surface location for collection. Generally, a wellbore is drilled, and a production completion is moved downhole to facilitate production of desired fluids from the surrounding formation. Many of the formation fluids, however, contain particulates, e.g. sand, that can wear or otherwise detrimentally impact both downhole and surface components.
Gravel packing techniques, including frac packing procedures, are often used to control sand. In typical gravel packing operations, a slurry of gravel carried in a transport fluid is pumped into a well annulus between a sand screen and the surrounding casing or open wellbore. The deposited gravel is dehydrated, and the gravel facilitates blocking of sand or other particulates that would otherwise flow with formation fluids into the production equipment.
In some gravel packing operations, difficulty arises in obtaining uniform distribution of gravel throughout the desired gravel pack region. For example, a poor distribution of gravel can result from premature loss of transport fluid, which causes the creation of bridges that can prevent or reduce further distribution of gravel past the bridge. Also, certain manmade isolation devices, such as packers, can present barriers to distribution of the gravel slurry. Shunt tubes have been used to bypass bridges and/or manmade isolation devices to ensure complete gravel packing. However, upon completion of the gravel packing procedure, the shunt tubes can leave undesirable flow paths, e.g. an undesirable flow path past a packer. Mechanical valves have been used to close off shunt tubes, but such valves must be cycled and are limited to shunt tubes of small size.